How do I disconnect the H4N from USB Audio I/F mode? Simply pressing to the Power Off button doesn't when it is connected in this mode and I have had to remove the batteries to do so. But don't feel this is great for the device to do (?)

Ah sorry I forgot to mention - I can not press any other buttons when it is in this mode. No other buttons work when in USB Audio I/F Mode... it doesn't not let me do this... (Press 'Menu')...

It is like it is frozen there - but it is not, because it's still receiving signal (and working) but frozen in the USB AUDIO I/F section with me unable to leave or 'disconnect' unless I remove the batteries...while powered, on...